目的 研究气体温度对冷喷涂7075铝合金涂层性能的影响，以期为制备高性能涂层提供重要参考。方法 利用冷喷涂技术，在较高的工作气体压力（5 MPa）下，通过改变工作气体温度（450、500、550、600 ℃），采用氮气在纯铝基体上制备了大厚度7075铝合金涂层。采用光学显微镜（OM）、扫描电子显微镜（SEM）对涂层组织结构及孔隙率进行了分析测定，用维氏显微硬度法测定涂层硬度，通过拉伸实验测定涂层结合强度，研究了冷喷涂工作气体温度对7075铝合金涂层组织及沉积特性的影响。结果 工作气体温度在450~550 ℃范围时，对涂层组织及力学性能影响有限。当工作气体温度为450 ℃时，涂层孔隙率为0.14%，显微硬度为117.8HV0.1，结合强度超过55.3 MPa。但过高的工作气体温度并不利于冷喷涂7075铝合金涂层的制备，当喷涂气体温度达到600 ℃时，涂层孔隙率升高到4.2%。结论 仅采用廉价的氮气即可制备高致密度和高结合强度的冷喷涂7075涂层，当主气温度在450~550 ℃区间时，涂层微观组织和性能随气体温度变化不大，而过高的工作气体温度（600 ℃）并不利于冷喷涂7075涂层相关性能的提升。

The work aims to study the effect of gas temperature on the properties of 7075 aluminum alloy coating in order to provide an important reference for the preparation of high performance coating. 7075 aluminum alloy coatings with large thickness were prepared on pure aluminum substrates by cold spraying technique under high working gas pressure of 5 MPa and changing working gas temperature (450, 500, 550 and 600 ℃). Microstructure and porosity of the coatings were characterized by optical microscopy (OM) and scanning electron microscopy (SEM). Hardness of the coatings was measured by Vickers microhardness. Bonding strength of the coatings was measured by tensile test method. The effect of working gas temperature on the microstructure and deposition characteristics of cold sprayed 7075 aluminum alloy coatings was studied. The working gas temperature had limited influence on the microstructure and mechanical properties of the coatings in the range of 450 ℃ to 550 ℃. When spraying gas temperature was set at 450 ℃, the porosity was 0.14%, the microhardness was 117.8HV0.1, and the bonding strength was more than 55.3 MPa. However, too high working gas temperature was not conducive to the preparation of cold sprayed 7075 aluminum alloy coatings. When the gas temperature reached 600 ℃, the porosity of the coating increased to 4.2%. 7075 aluminum alloy coatings with high density and high bonding strength can be prepared by cheap nitrogen. When gas temperature is set in the range of 450 ℃ to 550 ℃, microstructure and properties of the coatings do not change much with the gas temperature and too high temperature (600 ℃) is not beneficial to the improvement of the related properties of 7075 coatings.